A Banksy mural, lost in London, is found in Miami

North Londoners are furious over a missing Banksy mural that was torn off a building in the Wood Green neighborhood of the city and has since resurfaced online at Fine Art Auctions Miami.

The high-profile mural by the mysterious street artist, no stranger to publicity stunts, depicts a boy on his knees, hunched over a sewing machine and stitching Union Jack bunting. It went up last May on the wall of a Poundland department store in advance of June's Diamond Jubilee Celebration for Queen Elizabeth II, and according to the Guardian newspaper, it's considered a commentary on child labor.

The mural was a popular draw to the neighborhood, attracting locals and tourists alike. It is now titled "Banksy Slave Labor (Bunting Boy). London 2012" on the auction site, and listed for $500,000 to $700,000.

According to the auction house, which specializes in "important Russian, Impressionist, Modern and Contemporary works," the mural was put up for sale by a known collector, who Fine Art Auctions Miami owner Frederic Thut declined to name.

"The collector signed a contract saying everything was aboveboard," Thut told the Sun. Thut was "not available" for further comment, a harried auction-house associate said Tuesday afternoon, when several calls yielded a busy signal.

"Banksy Slave Labor" is one of two pieces by the artist seen in the catalog for an auction scheduled for Saturday, along with "Wet Dog," painted in Bethlehem and valued at $600,000 to $800,000.

Interest in "Banksy Slave Labor" was such that the auction house created a "blanket statement" for all media inquiries: "FAAM has done all the necessary due diligence to ensure the ownership of the work," it reads. "Unfortunately, we are not able to provide you with any information by law and contract about any details of any consignment. However, we are more than happy to do that if you can prove that the works were acquired and removed illegally."

"Wet Dog" was among five privately owned six-ton wall reliefs included in the CONTEXT Art Miami exhibit "Banksy: Out of Context" at Art Basel 2012. The catalog for that show acknowledged that showing site-specific street art outside of its original environment is "a very divisive issue within the art community."

Alan Strickland, a London councilman, urged his Twitter followers to email the auctioneers in protest. He tweeted: "Pls RT. Save our Banksy from sale. Let's all email art company auctioning it on info@faamiami.com. Tell them to withdraw it from auction."

In an interview with the BBC, Strickland said residents of the neighborhood are "shocked and really astonished."

"Banksy gave that piece of art to our community, and people came from all over London to see it," Strickland said.